gtest-message.h (8011B)
1 // Copyright 2005, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above 11 // copyright notice, this list of conditions and the following disclaimer 12 // in the documentation and/or other materials provided with the 13 // distribution. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 16 // this software without specific prior written permission. 17 // 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 // 31 // The Google C++ Testing and Mocking Framework (Google Test) 32 // 33 // This header file defines the Message class. 34 // 35 // IMPORTANT NOTE: Due to limitation of the C++ language, we have to 36 // leave some internal implementation details in this header file. 37 // They are clearly marked by comments like this: 38 // 39 // // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM. 40 // 41 // Such code is NOT meant to be used by a user directly, and is subject 42 // to CHANGE WITHOUT NOTICE. Therefore DO NOT DEPEND ON IT in a user 43 // program! 44 45 // GOOGLETEST_CM0001 DO NOT DELETE 46 47 #ifndef GTEST_INCLUDE_GTEST_GTEST_MESSAGE_H_ 48 #define GTEST_INCLUDE_GTEST_GTEST_MESSAGE_H_ 49 50 #include <limits> 51 #include <memory> 52 53 #include "gtest/internal/gtest-port.h" 54 55 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \ 56 /* class A needs to have dll-interface to be used by clients of class B */) 57 58 // Ensures that there is at least one operator<< in the global namespace. 59 // See Message& operator<<(...) below for why. 60 void operator<<(const testing::internal::Secret&, int); 61 62 namespace testing { 63 64 // The Message class works like an ostream repeater. 65 // 66 // Typical usage: 67 // 68 // 1. You stream a bunch of values to a Message object. 69 // It will remember the text in a stringstream. 70 // 2. Then you stream the Message object to an ostream. 71 // This causes the text in the Message to be streamed 72 // to the ostream. 73 // 74 // For example; 75 // 76 // testing::Message foo; 77 // foo << 1 << " != " << 2; 78 // std::cout << foo; 79 // 80 // will print "1 != 2". 81 // 82 // Message is not intended to be inherited from. In particular, its 83 // destructor is not virtual. 84 // 85 // Note that stringstream behaves differently in gcc and in MSVC. You 86 // can stream a NULL char pointer to it in the former, but not in the 87 // latter (it causes an access violation if you do). The Message 88 // class hides this difference by treating a NULL char pointer as 89 // "(null)". 90 class GTEST_API_ Message { 91 private: 92 // The type of basic IO manipulators (endl, ends, and flush) for 93 // narrow streams. 94 typedef std::ostream& (*BasicNarrowIoManip)(std::ostream&); 95 96 public: 97 // Constructs an empty Message. 98 Message(); 99 100 // Copy constructor. 101 Message(const Message& msg) : ss_(new ::std::stringstream) { // NOLINT 102 *ss_ << msg.GetString(); 103 } 104 105 // Constructs a Message from a C-string. 106 explicit Message(const char* str) : ss_(new ::std::stringstream) { 107 *ss_ << str; 108 } 109 110 // Streams a non-pointer value to this object. 111 template <typename T> 112 inline Message& operator <<(const T& val) { 113 // Some libraries overload << for STL containers. These 114 // overloads are defined in the global namespace instead of ::std. 115 // 116 // C++'s symbol lookup rule (i.e. Koenig lookup) says that these 117 // overloads are visible in either the std namespace or the global 118 // namespace, but not other namespaces, including the testing 119 // namespace which Google Test's Message class is in. 120 // 121 // To allow STL containers (and other types that has a << operator 122 // defined in the global namespace) to be used in Google Test 123 // assertions, testing::Message must access the custom << operator 124 // from the global namespace. With this using declaration, 125 // overloads of << defined in the global namespace and those 126 // visible via Koenig lookup are both exposed in this function. 127 using ::operator <<; 128 *ss_ << val; 129 return *this; 130 } 131 132 // Streams a pointer value to this object. 133 // 134 // This function is an overload of the previous one. When you 135 // stream a pointer to a Message, this definition will be used as it 136 // is more specialized. (The C++ Standard, section 137 // [temp.func.order].) If you stream a non-pointer, then the 138 // previous definition will be used. 139 // 140 // The reason for this overload is that streaming a NULL pointer to 141 // ostream is undefined behavior. Depending on the compiler, you 142 // may get "0", "(nil)", "(null)", or an access violation. To 143 // ensure consistent result across compilers, we always treat NULL 144 // as "(null)". 145 template <typename T> 146 inline Message& operator <<(T* const& pointer) { // NOLINT 147 if (pointer == nullptr) { 148 *ss_ << "(null)"; 149 } else { 150 *ss_ << pointer; 151 } 152 return *this; 153 } 154 155 // Since the basic IO manipulators are overloaded for both narrow 156 // and wide streams, we have to provide this specialized definition 157 // of operator <<, even though its body is the same as the 158 // templatized version above. Without this definition, streaming 159 // endl or other basic IO manipulators to Message will confuse the 160 // compiler. 161 Message& operator <<(BasicNarrowIoManip val) { 162 *ss_ << val; 163 return *this; 164 } 165 166 // Instead of 1/0, we want to see true/false for bool values. 167 Message& operator <<(bool b) { 168 return *this << (b ? "true" : "false"); 169 } 170 171 // These two overloads allow streaming a wide C string to a Message 172 // using the UTF-8 encoding. 173 Message& operator <<(const wchar_t* wide_c_str); 174 Message& operator <<(wchar_t* wide_c_str); 175 176 #if GTEST_HAS_STD_WSTRING 177 // Converts the given wide string to a narrow string using the UTF-8 178 // encoding, and streams the result to this Message object. 179 Message& operator <<(const ::std::wstring& wstr); 180 #endif // GTEST_HAS_STD_WSTRING 181 182 // Gets the text streamed to this object so far as an std::string. 183 // Each '\0' character in the buffer is replaced with "\\0". 184 // 185 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM. 186 std::string GetString() const; 187 188 private: 189 // We'll hold the text streamed to this object here. 190 const std::unique_ptr< ::std::stringstream> ss_; 191 192 // We declare (but don't implement) this to prevent the compiler 193 // from implementing the assignment operator. 194 void operator=(const Message&); 195 }; 196 197 // Streams a Message to an ostream. 198 inline std::ostream& operator <<(std::ostream& os, const Message& sb) { 199 return os << sb.GetString(); 200 } 201 202 namespace internal { 203 204 // Converts a streamable value to an std::string. A NULL pointer is 205 // converted to "(null)". When the input value is a ::string, 206 // ::std::string, ::wstring, or ::std::wstring object, each NUL 207 // character in it is replaced with "\\0". 208 template <typename T> 209 std::string StreamableToString(const T& streamable) { 210 return (Message() << streamable).GetString(); 211 } 212 213 } // namespace internal 214 } // namespace testing 215 216 GTEST_DISABLE_MSC_WARNINGS_POP_() // 4251 217 218 #endif // GTEST_INCLUDE_GTEST_GTEST_MESSAGE_H_